Mill with grinding-ring.



' E. souvuzn. MILL WITH GRINDING RING.

APPLICATION 'FILED DEC. 4, I914.

Patented June 13, 1916.

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THE COLUMBIA FLANOORAPH c0. WASHINGTON, D. c.

inn.

EMILE BOUVIER, on ninnnnuzwin, SWITZERLAND; assienon TO THE rim/r or eEBRt'InEnBfiHLnR, O-F UZWIL, SWITZERLAND.

MILL WITH GRINDING-RING.

To all whom it may concern Be it known that I, EMiLr. BOUVIER, a citi-' zen of the Republic of Switzerland, residing enable others skilled in the art to which it,

appertains to make and use the same, reference being had to the accompanying drawmgs, and to letters or figures of reference marked thereon, which form apart of this 7 specification.

Mills with r wherein the material is ground by rolls or cylinders pressed to the inner surface of a grinding ring by means of springs 'or' through the medium of the centrifugal force. i V

During the passing of the material under a cylinder the latter moves away from the grinding ring an amount in, accordance to the size of the grains and in accordance to the resistance opposingthe grinding. Due to the great mass formed by the cylinder (break or guiding roll), its shaft bearing and lever linked thereto, the initial force for the removing of said cylinder from the,

grinding ring is very great, because not only the tension of the spring, but also the inertia of the mass has to be overcome, but the kinetic energy given to the mass will be of influence proportional to the moving of said cylinder and will counteract the tension:

of the spring. The material having passed the cylinder, the latter is brought back by the spring and will strike .or pound with force against the grinding ring due to the kinetic energy imparted to said cylinder. Thus by these known mills a large number of strokes occur due to the great mass of the parts moving during the grinding, these strokes being identical with loss of energy. By other forms of construction of such between ring 19 and roll 17. By arranging mills one of the grinding rolls or cylinders has a steady bearing, the two other bearings being movable and in other cases the pressing springs are replaced by the centrifugal force.

The object of the present invention is to eliminate the pounding by avoiding the moving of great masses. This is obtained by providing a flexible grinding ring and at least three grinding rolls or cylinders which more than one grinding rest against and operate to support the grlnding ring, whereby thegrinding of the material takes place between the] cylinders and the grinding ring in consequence of the flexibility. The grinding rolls or cylinders may rest. against the outer surface or against the inner surface of the grinding ring; more than three grinding rolls and ring may be provided.

In the accompanying drawings, Figure 1 is a vertical cross section of'one form of mill embodying my invention. Fig. 2 is a vertical cross section of a second form of con "1IldlIlg rings are known struction. Fig. 3 is a section on AA of Fig. 2, and Fig. 45 is the section of a third shown) and arranged within and resting against the inner surface of the gr nding ring 14. Contrary to the above mentioned mills of known construction according to the present invention, the grlnding ring 1% is resilient, yielding under a predetermined pressure, that 1s 1t 1s deforming, The resilient grinding ring 14 is rotated by the friction of the rolls 11, 12, and 13 of which only one, or two, or all three, may be driven by belt pulleys. The material is fed from a hopper 15 into the mill and comes successively between the grinding rolls 11, 12 and 13, and the grinding ring 1 1 and escapes .sidewise after it has been ground.

v In the form of construction shownin Figs. 2 3, the cylindrical grinding rolls 16, 17, and 18 Test against the outside of the resilient grinding ring 19 and are rotatable 1n bearings (not shown). Here thering 19 is also rotated by the friction of the grind;

ing rolls, only one, or two, or all three of them may be driven by belt pulleys 20 as shown in Fig. 3.

Thematerial fed from a hopper 21, comes first betwee n ring l9 and roll 16, and then the blade 22 either in the position indicated by dot and clash-lines or in the position indicated in full lines (Fig. 2) the ground material can either be led directly toward Patented June13, 1916. Application filed December 4,1914. Serial No. 375,515." I

' a different resiliency and may be driven by of grinding rolls may be used.

certain deformation of the form of the grinding ring is thus determined by the size of the particles of the material to be ground and also by the resistance of these particles to the comminuting.

The only mass Working during the grinding is that, corresponding to the weight of the deformed part of the grinding ring.

The grinding takes place without pounding,

that is, the grinding is obtained with a mini mum of effort. If rounded off grains are to be obtained, one of the grinding rolls may be driven with a speed different from that of one of the other grinding rolls.

The angular velocity of all grinding rolls may be equal. Instead of only a single grinding ring more of such rings'may be arranged next to one another, for instance three rings, as shown in Fig. 3; this can also be the case in the mill shown in Fig. 1. These rings can therefore have an equal or common grinding rolls (Fig. 3).

Corresponding to the diameter of the grinding ring a more or less greater number The minimum however is three.

The peripheral plane of the grinding rollers can also have another form than a cylindrical one. In Fig. l the peripheral plane of the grinding ring or rings 24 have a concave profile and the grinding roll or rolls 25 have a corresponding convex profile.

The working of a mill thus constructed is the same as the working of the hereinbefore described forms of construction.

I claim- 1. In a grinding mill, three rotatable grinding rolls in fixed relative position, and

a resilient grinding ring in frictional e11- gagement with sa1d rolls.

2. In a grinding mill, three rotatable grinding rolls in fixed relative position, a resilient grinding ring in frictional engagement with said rolls, and supported solely by the latter.

3. In a grinding mill, three rotatable grinding rolls in fixed relative position, a resilient grinding ring in frictional engagement with said rolls, supported solely by the latter, and means to positively drive one of said rolls.

4. In a grinding mill, three rotatable grinding rolls in fixed relative position, a resilient grinding ring in frictional engagement with said rolls, supported solely by the latter, and means to positively drive two of said rolls.

5. In a grinding mill, a plurality of rotatable grinding rolls in fixed relative position, and a resilient grinding ring in external con tact with said rolls and supported solely by the latter.

6. In a grinding mill, three rotatable grinding rolls in fixed relative position, and a resilient grinding ring in external contact with said rolls and supported solely by the latter.

7. In a grinding mill, a resilient grinding ring, three rotatable grinding rolls in fixed relative position uniformly distributed around and in contact with the external periphery of the ring.

8. In agrinding mill, a resilient grinding ring, three rotatable grinding rolls in fixed relative position uniformly distributed around and in contact with the external pe riphery of the ring, and means to positively drive one or more of said rolls.

9. In a grinding mill, a plurality of resilient grinding rings having a common axis, three rotatable grinding rolls in fixed relati e position uniformly distributed around and in frictional engagement with the external peripheries of said rings, and means to rotate one of said rolls.

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

EMILE BOUVIER. Witnesses:

FRANK FIMMKE, EMIL MEILE.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents, Washington, D. G. 

